• 한국환경복원기술학회지
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• 제12권1호
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• pp.82-91
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• 2009

Research was initiated to investigate vegetation characteristics of native ('Pureundle' and 'Sewon') and introduced ('Brilliant' and 'Midnight') Kentucky bluegrass (KB, Poa pratensis L.) varieties by soil-seed applying system on a cut-slope in May 17, 2008. There were no statistic differences observed in soil hardness and soil moisture content while significant differences were observed in surface coverage rate, height and disease occurrence in native and introduced KB varieties. The introduced 'Brilliant' KB was highest in the surface coverage rate from the early period of seeding to August 11, 2008. The surface coverage rate of introduced varieties were high when compared to native varieties in their early growth stage. But native varieties reached to equal surface coverage rate with the introduced varieties when three months after seeding. The height of 'Pureundle' and 'Brilliant' KBs were high compared with Midnight and Sewon KBs. 'Pureundle' and 'Brilliant' KBs were damaged by disease whereas there were no disease occurrence in 'Midnight' and 'Sewon' KBs. Probably, the disease occurrence was close related with the height of KBs not with native and introduced KB varieties. These results indicate that the growth of KB on a cut-slope are statistically affected by varieties in early growth stage of this experiment but reach equal rate between native and introduced KB varieties in three months after seeding. This growth characteristics implies the huge potential of native KB varieties seeding for cut-slope vegetation. Considering that native KB varieties are adapted to a environment and have no risk of causing disturbance to the ecosystem compared to the introduced KB varieties, the use of them as native varieties for a cut-slope vegetation can be increased.

• 한국기후변화학회지
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• 제6권4호
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• pp.379-388
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• 2015

The purpose of the this study was to provide basic data on reasonable management for Abies koreana in Mt. Jiri through analysis the ecological characteristics of Abies koreana forests on Seseok. Due to low soil pH (4.26), high organic matter (10.5%) and total N (0.32%), the soil properties of A. koreana forest on Seseok are different from those of other forest soil in Korea. According to the result of importance value analysis, A. koreana (70.5) for tree layer, A. koreana (37.6) and Rhododendron schlippenbachii (20.8) for subtree layer and A. koreana (12.6), Sasa borealis (11.5) and Acer pseudosieboldianum (11.2) for shrub layer were high, respectively. The species diversity of Shannon was 0.425 for tree layer, 0.869 for subtree layer and 1.320 for shrub layer. Evenness and dominance for all layers ranged from 0.365 to 0.894 and 0.187 to 0.635, respectively. Height growth according to DBH of A. koreana on Seseok was relative high. Annual mean tree ring growth of A. koreana showed up 1.372, 1.557 and 1.483 mm/yr for small, middle and large diameter tree, respectively. Considering the importance value, distribution of seedling, height growth and ring growth, A. koreana forest on Seseok in Mt. Jiri will be maintained as the major population from now on.

• Geomechanics and Engineering
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• 제28권5호
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• pp.521-529
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• 2022

This research work deals with the development of air pluviation method for preparing uniform sand specimens for conducting large scale laboratory testing. Simulating real field conditions and to get reliable results, air pluviation method is highly desirable. This paper presents a special technique called air pluviation or sand raining technique for achieving uniform relative density. The apparatus is accompanied by a hopper, shutters with different orifice sizes and numbers and set of sieves. Before using this apparatus, calibration curves are drawn for relative density against different height of fall (H) and shutter sizes. From these calibration curves, corresponding to the desired relative density of 60%, the shutter size of 13mm and height of fall of 457.2 mm, are selected and maintained throughout the pluviation process. The density obtained from the mobile pluviator is then verified using the Dynamic Cone Penetrometer (DCP) test where the soil is poured in the box using defined shutter size and fall height. The results obtained from the DCP test are averaged as 60±0.5 which was desirable. The mobile pluviator used in this research is also capable of obtaining relative densities up to 90%. The instrument is validated using experimental and numerical approach. In numerical study, Plaxis 3D software is used in which the soil mass is defined by 10-Node tetrahedral elements and 6-Node plate is used to simulate plate behavior in the validation phase. The results obtained from numerical approach were compared with that of experimental one which showed very close correlation.

• 한국토양비료학회지
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• 제44권1호
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• pp.29-37
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• 2011

The experiment was carried out to find the effects of transplanting time and vinyl-film mulching treatment on the growth of artemisia by randomized block design with three replications. The experiment site ($100{\times}130$ m) was temporally established in the south-eastern part of Saemangeum reclaimed tidal land (near Gwanghwal myun, Gimjae-gun, Jellabukdo). Artemisia plants had been partly suffered from salt injury, because soil salinities in some area during growing period had been measured higher than 10 dS $m^{-1}$. Growth of plant height and survival ratio of transplanted plants had been significantly correlated with soil salinity and then the regression equations between plant height (y) and soil EC (x) and between survival ratio (y) and soil EC (x) were expressed as y=-16.59ln(x)+43.852 and $y=0.6453x^2-17.566x+103.99$, respectively. It was concluded that early transplanting and vinyl mulching was more beneficial for biomass production of artemisia, because biomass was 6.41 times more in the early transplanting than in the late transplanting, and 2.63 times more in the vinyl-film mulching than in the no mulching treatment.

• 한국지반환경공학회 논문집
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• 제4권2호
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• pp.27-37
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• 2003

본 연구에서는 삼축 조건하에서 지오셀-흙 복합체의 응력-변형 거동과 지오셀에 의한 강도증가를 고찰하였다. 연구를 위하여 직경 50mm, 높이 100mm인 시료 중앙에 직경 50mm, 높이는 각각 35, 50, 70mm인 연성의 모형셀을 넣고 3개의 밀도 변화에 따른 일련의 삼축시험을 수행하였다. 시험결과 지오셀의 구속은 모래의 등가점착력을 유발시키는 것으로 나타났으나 점착력은 지오셀 재료의 특성에 관계되는 것으로 나타났다. 기존의 지반보강재에 의한 강도증가가 등가점착력의 유발만 나타난 것과는 달리 본 연구에서 사용된 탄성의 고무지오셀 재료는 등가점착력의 유발뿐만 아니라 내부마찰각도 증가시키는 것으로 나타났다. 지오셀-모래 복합재의 강도를 쌍곡선 모델에 적용시킨 결과 지오셀 복합재료의 거동이 일반 흙과는 거동이 다르므로 적용된 설계하중 범위에서의 첨두강도 결정이 거동을 묘사하는데 중요한 것으로 인식되었다.

• 인간식물환경학회지
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• 제23권5호
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• pp.507-519
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• 2020

Background and objective: This study analyzed the growth characteristics, in relation to the soil moisture content, of trees planted in an environment with limited soil depth to provide the baseline data for effective irrigation management. Methods: The experimental treatment was divided into soil moisture contents (SMC) of 20%, 15%, 10%, 5%, and 1%, and the respective watering times were set accordingly. As for plant materials, Nandina domestica, Euonymus alatus, Thuja occidentalis, Hibiscus syriacus, Pinus densiflora, and Pyracantha angustifolia, were chosen for this study, because they are highly likely to be used in urban street environments. Results: The minimum irrigation point suitable for each species was determined by considering various aspects of visual quality and water efficiency in terms of plant growth, including characteristics such as height, root diameter, rootlet development, and weight. Our results indicate that N. domestica should be watered so that the moisture content of the soil is of at least 5%, based on the balance between the stem and roots, as well as on visual quality. E. alatus and P. angustifolia are suitable for watering that results in at least 10% SMC, considering the height, root growth, weight, and visual quality of plants. As for T. occidentalis, it showcases moderate growth with a soil moisture content of at least 5%. Finally, the minimum irrigation time required to obtain 15% SMC is appropriate, in terms of plant growth, fresh weight, and visual quality, for H. syriacus and P. densiflora. Conclusion: This study suggested a basic irrigation guideline for container gardens where trees planted in environments with limited soil depth can be managed so that they are visually appropriate and in good condition of growth.

• 농업과학연구
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• 제50권2호
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• pp.223-234
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• 2023

Appropriate fertilization methods are required according to species to supply necessary nutrients to plants and prevent soil environmental contamination in nurseries. In this study, the effects of nitrogen and phosphorus fertilization on the growth of Liriodendron tulipifera and soil characteristics were investigated. After 16 fertilization treatments (4 levels of nitrogen × 4 levels of phosphorus) were applied to one-year-old L. tulipifera seedlings at the Yongmun Nursery Station of the Korea Forest Service, height, root collar diameter (RCD), biomass, leaf nutrients, and soil characteristics were investigated. The height increased as the amount of nitrogen and phosphorus fertilization increased, and the RCD was the highest in the ×2 treatment. Biomass growth was on average 40.0% higher for the treatment with high nitrogen fertilization compared to the low nitrogen treatment. The seedling quality index was the highest with nitrogen and phosphorus ×2 treatment. Leaf phosphorus and magnesium concentrations decreased when nitrogen fertilization was applied, and leaf potassium concentrations decreased as nitrogen fertilization increased. Soil pH and exchangeable potassium decreased as the amount of phosphorus application increased, and exchangeable magnesium decreased as the amount of nitrogen application increased and increased as the amount of phosphorus application increased. Considering the growth of L. tulipifera seedlings and changes in the soil characteristics at the nursery stage, twice the standard fertilization amount is the appropriate fertilization amount for nursery of the Yongmun Nursery Station. It is expected that this study will contribute to improving nursery soil fertilization management technology for healthy seedling production.

• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.31-34
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• 2006

The experiment was conducted to determine the effects of cutting interval and cutting height on the yield and nutrient composition of hedge lucerne (Desmanthus virgatus) when grown on a sandy soil in the Northeast of Thailand. The cutting intervals compared were 30, 40 and 50 days between harvests and the cutting heights 30, 40 and 50 cm above ground level. The experiment was a $3{\times}3$ factorial layout in a randomized complete block design with 4 replications-giving a total of 36 plots each $3{\times}3m^2$. Harvested plant material was weighed, dried and the ground subsamples taken for analyses of crude protein (CP), crude fiber (CF), ash, ether extract (EE) and nitrogen-free extract (NFE). At the last harvest the hedge lucerne samples were separated to determine leaf to stem ratios and then analyzed for nutrient composition in the leaf and stem. Results showed that increasing the cutting interval (i.e. advancing age of maturity) increased dry matter and nutrient yields significantly. In terms of nutrient content, it also increased the crude fiber, ash, ether extract and nitrogen free extract percent in the plant. However, crude protein percent was markedly decreased as the cutting interval increased. Increasing cutting height had no effect on dry matter yield and yields of nutrients, but in terms of nutrient content, it increased crude protein and ash content, but decreased crude fiber content. The percent EE and NFE in the plant was unaffected by cutting height. From the results presented it is clear that cutting a stand of hedge lucerne every 40 to 50 days will achieve greater dry matter and nutrient yields than cutting more frequently, at 30 days. The cutting height at harvest, whether 30, 40 or 50 cm above ground level had no effect on dry matter or nutrient yields of hedge Lucerne. Hedge lucerne therefore offers the Thai poultry farmer a useful alternative protein supplement for poultry diets rather than relying on the more expensive soybean meal. As it can be readily and successfully grown on a range of soil types and climates throughout Thailand, hedge lucerne also offers the Thai farmer a valuable additional source of income.

• 한국지반환경공학회 논문집
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• 제20권1호
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• pp.43-49
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• 2019

본 논문에서는 쏘일네일 설계에 위상최적화 기법을 도입하여 비탈면 높이별로 필요로 하는 보강력을 최적화하였다. 최대 비탈면 높이에서의 최적설계 결과를 보강형상밀도화하여 비탈면의 높이 변화에 따라 적용 시 쏘일네일의 수평간격의 위상최적화가 가능하였다. 단계별로 비탈면 높이를 달리하여 한계평형해석을 수행하고 쏘일네일의 수평간격이 고정값일 때 초과되는 안전율을 확인하였다. 비탈면 높이에 따른 필요 보강력을 밀도화 함으로써 최적화의 과정을 효율적으로 수행할 수 있었다. 또한 쏘일네일의 축력을 보강형상밀도에 반영하기 위하여 유한요소법을 이용하여 부재력을 반영하였다. 보강형상밀도를 산정하여 비탈면 높이별로 위상최적기법을 적용 시 비탈면 높이마다 기준안전율을 만족하는 반복적인 재해석과정을 효과적으로 감소시킬 수 있어 수평간격을 위상 최적화하는 방법이 경제적인 설계에 활용도가 높을 것으로 판단된다.

• 한국토양비료학회지
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• 제42권3호
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• pp.145-151
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• 2009

논에서 전환된 포도원(전환포도원)의 전환 후 년수 및 토양특성별 물리적 특성변화 양상을 구명하여 전환지 생산성 향상을 위한 합리적 토양 관리대책을 제시코자 전환지가 많은 경북 김천, 영천지역을 중심으로 포도원과 인근 벼 재배지 50개 지점을 조사 분석한 결과 전환포도원의 이랑 높이는 토성이 세립질이고 배수가 불량할수록 높았고, 토양단면 내 반문의 출현깊이(Ap층 두께)는 조립질 토양에서 깊은 경향이었음. 전환지는 인근 유사토양 벼 재배지 작토층 토색의 경우 색상이 밝아지는 경향을 보여 회색도가 벼 재배지의 경우 20인데 비해 전환지는 5로 감소했고, 이 경향은 토양 배수조건이 양호한 토양에서 현저하였음. 전환여부에 따른 투기도 차이는 토심10cm 이하에서 현저했고 토심 30cm 이하에서는 뚜렷한 차이가 없었고 전환지에서 투기도에 미치는 토양특성의 영향은 세립질의 경우 이랑의 높이가, 조립질은 배수등급이었다. 전환포도원의 물리성은 전환 후 년수가 경과함에 따라 공극율과 내수성입단이 증가하는 경향이었고, 원추관입저항의 경우 휴립한 부위는 $5kg/cm^2$ 이하인 반면, 그 이하의 부위는 $10kg/cm^2$ 이상을 보였음. 이상의 결과로 볼 때 전환포도원의 토양특성은 세립질보다 조립질이 쉽게 변하는 경향이었고, 배수불량인 세립질토양에서는 고휴재배 등 적절한 표토관리가 요구되었다.